Caption: Flerovium (Fl). Diagram of the nuclear composition and electron configuration of an atom of flerovium-289 (atomic number: 114), the most stable isotope of this radioactive element. The nucleus consists of 114 protons (red) and 175 neutrons (blue). 114 electrons (green) bind to the nucleus, successively occupying available electron shells (rings). Flerovium, named after Georgy Flyorov and first synthesised in 1999, is a transactinide of unknown properties in group 14, period 7, and the p-block of the periodic table. There are two nuclear isomers of flerovium-289, with half-lives of 2.6 seconds and 1.1 minutes.